Introduction

In today's world of extremely large and complicated software systems, stability and maintainability are usually considered the major goals for most software projects, whereas optimization has not been widely seen as a worthwhile goal since the 2000s. This is because of the rapid acceleration of hardware technology that overtook software demands on a regular schedule.

For many years, it seemed like the hardware improvements would continue to keep up with the performance demands of software, but applications continued to grow larger and more complex. Low-level native-compiled languages such as C and C++ dropped in popularity compared to less performant but easier to use interpreted languages such as Python or Ruby.

By the late 2000s, though, the trend of CPU transistor count (and performance) doubling every 18 months (a consequence of Moore's Law) had stopped, and performance improvements had flattened out. The expectation of 5 to 10 GHz processors being widely available...